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Had to repair a broken weld on my top and it got me to thinkin' 'bout gettin' a new one. Had a local fabricator tell me that no one is using stainless steel any more because of weight, $, time involved in fabrication. Said 95% or more of all new boats had anodized aluminum tops. Is this correct? Seems reasonable but I'm wary of just about anyone who sells anything, even people who I've done business with in the past. Anyone out ther with a new ride that has a steel top from the factory? Any other advice on the subject out there?

Aluminum is your ONLY option!Even if you could tolerate the extera weight, stainless won't take the stress. It's brittle, and cracks will eventually appear around the welds. It will come apart soon after.Stainless weld joints also tend to bleed a lot of rust.

I wish I had a SS Top. My aluminium frame has pitted and looks horrible. When the welds break, there is a thick bead. Also the corrosion with the ss fasteners. If you get SS, make sure it is 316L, as it has more nickel to prevent rust. Fabricators have gotten away from SS because it is a lifetime product and takes longer to weld and polish, meaning more $$$. If you break a weld, you can reweld it and polish it and never know it had broken.

I am certainly no expert, but I believe that it is aluminum that is more brittle and will crack. It becomes more brittle over time as it flexes. A properly constructed top made of either should not crack for many, many years... `10+ years if you ask me.

Aluminum is certainly lighter, so a must if weight is a concern.

I think maintenance is the same if both are properly maintained from the begining.

How about if Bullshipper had said that for a given size, aluminium has a weight that is one-third the weight of steel? So, if the total weight of a steel hardtop frame is some value, say 300 pounds, then an equivalent aluminum frame would weigh only 100 pounds.

In my mind, aluminum is the only weigh (pun intended) to go. The problem I see with most aluminum frames is they are made from aluminum that has been anodized before it is welded. From a welding standpoint anodizing is dirty aluminum and dirty welded aluminum is prone to cracking. Ever noticed how crappy the welds look compared to the anodized tubing? A better solution would be to weld unanodized aluminum and then anodized the frame, welds and all. Probably cost prohibitive for most however.

Anodized aluminum all the way. Anything can break, but if built right aluminum will last long and also it is easier to find someone to repair aluminum if need be. Aluminum does not get as hot from sun as much as SS. Heat travels and disopates much faster in aluminum than SS. That is why cooling fins on electronics and AC units are made from it.

6061 03 6063 Aluminum costs about 25% less per lb as 316L Stainless, and weighs almost 3 times less. Plus the SS requires time consuming polishing.

To be more specific:
2 - 20' long pieces of angle made out of stainless steel and aluminuim will weigh differently by a factor of about 2.80:1. If I remember right, one cubic meter of aluminum weighing about 2770 kgs, and 1 cubic meter of SS weighing about 7770 kgs.

316L plate goes for about $2.65 per lb where I live, and 5083 aluminum plate will run about $2.25 a lb. Shapes are more money and only come in 6063 and 6061 al alloy.

For instance 1.5" schd 40 al pipe is $36.75 a 20' length, and 1" runs $22.75 for a 20'length, as quoted yesterday from Metelsales, N. Orleans.

I wish I had a SS Top. My aluminium frame has pitted and looks horrible. When the welds break, there is a thick bead. Also the corrosion with the ss fasteners. If you get SS, make sure it is 316L, as it has more nickel to prevent rust. Fabricators have gotten away from SS because it is a lifetime product and takes longer to weld and polish, meaning more $$$. If you break a weld, you can reweld it and polish it and never know it had broken.

I have a SS on one boat, and an aluminum one on the other. The aluminum is holding up a lot better, and requires a lot less maintenance.

Aluminum welds are easy to repair, and $ for $, pound for pound, the Al is stronger IMHO.

Had to repair a broken weld on my top and it got me to thinkin' 'bout gettin' a new one. Had a local fabricator tell me that no one is using stainless steel any more because of weight, $, time involved in fabrication. Said 95% or more of all new boats had anodized aluminum tops. Is this correct? Seems reasonable but I'm wary of just about anyone who sells anything, even people who I've done business with in the past. Anyone out ther with a new ride that has a steel top from the factory? Any other advice on the subject out there?

in the real world a stainless ttop should come very close in weight to an aluminum one. why? Stainless does weigh more per cubic volume. But, stainless is far stronger so the ttop is fabricated from much thinner material to yield a comparatively strong ttop. For example my stainless ttop weighs 89 pounds. a comparable aluminum ttop might weigh 80. Pretty close. Another issue with stainless having a bad reputation for cracking at welds comes from the fabricator wanting his welds to be smooth. If the stainless tube is .065 thick and the fabricator &quot;cleans up&quot; the weld and in the process grinds away .030 of base metal, yeah, the tube is now only .035 thick. down by half. So it cracks thru the thin place and folks blame the material not the over polishing. That why I never grind down a stainless weld, they are all puddle welds to maintain full material thickness.Fabricating stainless properly requires a higher skill level than aluminum and a higher investment in fab tools.** Last thought, why does a ttop crack?** cracks occur in all metals at the point of max repetitive stress.* too much weight aloft or poorly thought out bracing allows stress to accumulate at some point of concentrated motion resulting in a crack.** re-welding alone rarely fixes the problem as the metal around the crack has become hard and brittle and a new crack will form with haste.** Good initial geometry is hugely important.* good fabrication.** and quality metal, stainless or aluminum have their place.**

Charlie, you have pretty much nailed that one.
WE get what we pay for ,metals ferrous and nonferrous come in all diff. grades .If we buy quality and use the correct welding process any of the above materials shouldn't be a problem it comes down to personal choice. BTW I use the same welder to weld both materials aluminum uses a-c with the high freq. and stainless uses dc and ya better know what your doing aL turns to a mirror puddle then falls away if your not paying attention and stainless will blister and burn on the backside with to much heat . Yes it's an art that takes lots of practice always check some of your welders work before he/she works for you.

welder, good points! You mention blistering stainless with too much heat. In an effort to save fabrication time most fabricators try to run a continuous bead which raises the heat tremendously and makes the metal surrounding the weld brittle. We weld one little puddle at the time, pause, weld another puddle, pause, weld... etc. its time well invested. I look at my puddle welds and smile.